1. Field of the Invention
The present invention relates to a disk drive for recording to or reproducing from a disk, and particularly to a disk drive preferably used as an external storage of electronic apparatuses such as personal computers, word processors or the like.
2. Description of the Prior Art
Disk drives carry out recording to or reproducing from disk-shaped recording media such as magnetic disks, laser disks or the like. The disk drive is constructed to perform recording to or reproducing from a disk as follows: a disk, the recording medium, is inserted into the disk drive and is ejectably loaded thereto; the disk is rotated by a driving motor; heads are made to come into contact with or made to approach a surface of the disk; and writing data into or reading data out of the disk is carried out with the heads moving. In this case, the heads are mounted on a carriage which is moved by a driving motor, so that the heads are moved on the disk in the radial direction (seek operation). An example of the disk drive is shown in Japanese Patent Application Laying-open No. 219,449/1990 (U.S. Ser. No. 07/392,045).
The disk drive comprises on a base that supports respective component parts of the disk drive, an installation and removal means for installing or removing the disk, a disk rotation drive means for rotating the disk by the motor, a head seek means for moving heads on the disk in the radial direction to place the heads on a target track, a head loading means for loading or unloading the head to or from the disk, and the like. In addition, there are provided a control circuit for controlling the entire disk drive, and a connector for a power supply. The control circuit is connected to a host computer system via an interface so that the control circuit receives data from and supplies data to the host computer system.
In general, the installation and removal means has a cassette guide that supports a disk cassette in which the disk is housed, and guides the disk cassette into the disk drive so as to install it on the disk rotation drive means and guides the disk cassette out of the disk drive so as to remove it from the disk rotation drive means, a slide plate that has a cam portion which engages a part of the cassette guide to lower or raise it, and is movable in directions in which the disk cassette is installed or removed, and a latch member that controls an ejection of the disk cassette in response to the movement of the slide plate. The disk drive has a shutter opening means for opening a shutter of the disk cassette by engaging the shutter in accordance with the installation of the disk cassette. The shutter opening means are arranged so that the latch member functions as a engaging member which engages the shutter, or are arranged so that the engaging member, which is rotatably supported to the cassette guide, can engage the shutter.
The head loading means, on the other hand, has head arms which support the heads on an end thereof respectively and head loading springs: one of the head arms is vertically rotatably mounted on fulcrums provided in a carriage which moves for the seek operation, and is pressed towards the disk by the loading springs so that the head is loaded, or is rotated upwards with the elevation of the cassette guide so that the head is unloaded.
Components described above of the disk drive are housed in the base shaped like a box, the opening of which is covered by a cover for providing a dustproof, magnetic shield.
When such disk drives are Used as external storage of the electronic apparatuses such as personal computers or word processors, they are sometimes constructed as independent apparatuses. In general, however, they are incorporated into the main bodies of the electronic apparatuses. As the electronic apparatuses reduce their size and increase their portability, reduction in size, weight and thickness of the disk drives is increasingly required.
In the head loading means of the conventional disk drive, when the head is unloaded (elevated), the head arm is rotated about the fulcrum while maintaining its linear shape. This presents a problem that the tips of the head arms are elevated high, and hence the thickness (the height) of the disk drive becomes large.